Omega Products HSK63A Face Mill Arbor - Through Coolant - G2.5 - 25,000RPM - 16mm Spigot - 100mm Gauge LengthHSK63A Face Mill Arbors with Through Coolant are designed for high speed milling operations that require efficient cooling of the cutting tool and workpiece. These arbors feature a precision HSK63A shank that provides maximum rigidity and accuracy, and a G2. 5 coolant system that delivers coolant directly to the cutting edge for improved tool life and chip evacuation. They can accommodate face mills with a bore diameter ranging from 16mm to 32mm, and